Portable electric sprayer



Aug. 19, 1947. w. F. GORDON ETAL PORTABLE ELECTRIC SPRAYF Filed June 10, 1940 2 Sheets-Sheet l INVENTORS v WALL/HM E GORDO/Y WW Z R i H B g- 19, 1941- I w. F. GORDON ETAL 2,253,071

PORTABLE ELECTRIC SPRAYER Filed June 10, 1940 2 Sheets-Sheet 2 IWIM.

INVENTORS W/LL IFIM E6 0900/) WHL 715 H. MHESH C1 ATTORNEY Patented Aug. 19, 1941 2,25s,071 PORTABLE ELECTRIC SPRAYER William F. Gordon, West Bedding, Conn, and Walter H. Marsh, Grafton, Pa., assignors, by direct and mesne assignments, to Atlas Electric Sprayer Corporation, New York, N. Y., a corit owns!) STATES PATENT OFFICE poration of New York ApplicationJune 10, 1940, Serial No. 339,658

2 Claims.

The present invention relates to an electric spraying device adapted for atomizing the liquid content of a container associated therewith and, more particularly, to an electric sprayer adapted for vaporizing liquid insecticides and exterminants to provide a vapor blanket over the area sprayed,

For many years, spraying and atomizing devices of many different types have been used for the purpose of providing a mist or cloud of an insecticide having a mineral oil, kerosene or like base. These devices have included rubber bulb atomizers and piston spray guns and have been employed to some effect in open spaces, especially upon flying insects, such as flies, gnats, mosquitoes and the like. However, these prior art devices suffered the defect of producing a mist which contained a great many relatively large liquid particles. These droplets became focal points for condensation, which in turn further enlarged them. Two main disadvantages resulted therefrom; first, the droplets fell upon woodwork finishes, glassware and tapestry, and other upholstery materials, forming a deposit thereon, which considerably reduced the usefulness of the insecticide, and, secondly, the mist, being of high specific gravity, was unable to penetrateinto cracks, crevices and fabric pores. As a result of this inability to flow into very confined spaces, roaches, bedbugs, ants and other insects of this type were able to secrete themselves in comparative safety, and flying insects laid their eggs in such places without harm to eggs, larvae, and pupae thus secluded. Thus, while these difliculties and disadvantages of prior art devices were generally. known, no satisfactory solution of the problem, so far as we are aware, was ever made.

We have discovered that this pressing roblem can be solved in a relatively simple and inexpensive manner.

It is an object of the present invention to provide a means for overcoming the difficulties and disadvantages of prior art spraying devices.

It is another object of our invention to provide means for atomizing liquids whereby an extremely fine spray is produced.

It isia further object of this invention to provide a portable electric spraying device for atomizing the liquid content of an associated container.

It is also the intention of the present invention to contribute a means for vaporizing insecticides having mineral oil, kerosene or the like as a carrying base, whereby a substantially gaseous exterminant can be provided. v

Our invention also, contemplates the provision of a spraying device for vaporizing oilbase insecticides to produce gaseous exterminants of specific gravity only slightly greater than unity, whereby the gaseous exterminant can drift in the air and permeate any cracks, crevices and fabric pores in the area where it is applied.

It is also within the contemplation of the invention to provide, a sprayer for so finely atomizing oil-base insecticides that the tendency developed therein is more toward evaporation than condensation and thus to provide a vaporiz ing blanket from which the amount of condensation is so low as to besubstantially negli- I gible.

Still another object of our invention is to provide a sprayer for vaporizing oil-base insecticides, whereby a gaseous blanket is formed which displaces the air in the area where it is applied and so compels flying insects to emerge from hiding places and to fly into the insecticide blanket.

Moreover, the present invention has in view the contribution of a portable, power-driven sprayer for dispensing liquid insecticides which is sufficiently small, compact and inexpensive to be of practicable use for small users.

Our. invention also provides an electric sprayer for atomizing liquids which is light, compact, handy, portable, easily operated, inexpensive both to make and to operate, and highly efficient in service.

Other objectsand advantages of the present invention will be apparent from the following description, taken in conjunction with the drawings, in which:

Fig. ,1 illustrates a perspective view of our improved portable spraying device, with part of the liquid container broken away;

Fig. 2 depicts a fragmentary side elevation of the same, largely in cross section; and

Fig. 3 represents a plan view of our improved sprayer, taken on line 3-3 of Fig. 2, with part broken away to show the air vent to the liquid container.

Broadly speaking, the present invention provides an air compressor comprising a motordriven rotor eccentrically mounted in its casing and having fins adapted to make rubbing contact with the inner wall of the casing over its entire area. Two orifices are provided in the casing, an air inlet at such point of the casing 3 of the same height as the rotor.

inner wall where the rotor is diverging from the wall in the direction of rotation of the rotor, and a compressed air outlet at a section where the wall and the rotor are converging relative to the direction of rotation of the rotor. In this manner, the fins associated with the rotor compress the air, and it is then sup-' plied through an orifice across the end of a tube which is communicably connected with liquid in a container below. The surface of the liquid is open to atmospheric pressure, and the stream.

of air blowing across the top of the tube forms .a partial vacuum, thus causing the liquid to rise in the tube into the air current. This air current is so strong that the liquid is instantly vapower-driven, air-blowing element can be constructe'd most compactly, so thatit cannot be easily broken and so that it will be adaptable to use with containers of varying volume constructed with tubes of appropriate length,

For the purpose of giving the art a better -understanding of our invention, a description of a specificembodimentofthe present invention will be provided.

Referring to Figs. 2 and 3, in a casing A, a rotor "is keyed to the shaft 2 of a motor and is :4

mounted eccentrically in a cylindrical chamber The rotor has a plurality of slots 4 extending from the central region of the rotor to its circumference for the full heightof said rotor, and each slot is equipped with a freely-moving fin'5 of length no greater thanthe length of the slot and adapted to --make rubbing contact with the inner 'wall of thecylindrical chamber.

The chamber wall is intersected by an air inlettube 6 at a point 'of' thewall relatively close to'fthe center line of motor shaft 2 and'at that section of thewall where therotor is diverging from the wall in the direction of rotation of the rotor. Thechamber wall is also intersected by a-compressed air outlet 1 at-anotheripoint of the wall relatively 'closeto the center line of the motor shaft. but beinglocated where the wall and the-rotor-are-converging relative to the direction of rotation of the rotor. scoop-like groove to in the chamber wall leads from the inlet tube in the direction of divergence of 'wallfrom rotor. The compressed airzoutlet communicably connects with an orifice'8, which in turn communicates with an expansionspace 9 of truncated conical --shape. A tube'of small diameter *lis positioned with "its upper section in said conical expansion space '9, the top end of said tube being in contact with the lower part of-ori'fice 8. The tube-or tubular passage extends-downward -to the bottom of the casing, and its lower end there forms thecenter of the top of a cap ll having a female thread. This cap is in threaded contact with the male thread of a port :12 of zliquidcontainer [3. The port l2 of said container .is equipped with a plug i4 having :at :its center a downwardly extending tube 15 of such length as to come within a small fraction .of an inch of the bottom of the container. It will The evident from this description At this point, it communicates with A short and narrow that tubes l0 and [5 are in substantial alignment and that the bottom of tube I!) is in contact with the top of tube l5 when the cap H is screwed tightly upon the port l2. A gasket l6, preferably of synthetic rubber so as not to be affected by vapors of the liquid content of container I3, is provided for better sealing the two tubes together.

The inside of cap H has an annular recess H of outer diameter approximately equal to the inside diameter of the cap, and a small orifice l8 connects this recess with the outside air. In the plug l4, another orifice l9 also communicates with the recess [1, when cap and port are in threaded contact, so that the surface of the liquid in the container is open to the atmosphere.

When ready for use, our improved sprayer is mounted as shown in Fig. 1. The motor casing B is mounted above rotor housing or casing A, and a motor of sufficient size therein is connected by lead Wires 20 to a source of power. A toggle switch 2| is provided at the top of the motor casing -B for conveniently starting or stopping the motor. Considering the conical expansion space or aperture 9, from which the spray emerges, as the front of our device, a handle C of suitable size and balance is provided at the top rear of the motor casing for the purpose of conveniently carrying and supporting the device while in operation. The toggle switch 2| can be most conveniently located in proximity to this handle, so that it can be easily operated with thumb and forefinger.

The'operation of our improved spraying device is extremely simple. When the motor is started by flicking the toggle switch 2!, rotor I turns in a clockwise direction (see Fig. 3) and throws fins 5 by centrifugal force against the wall of chamber '3. At the widest space between rotor and wall, fins 5 slide farthest out of slots 4, and, as the rotor turns, the converging wall surface :forces the fins back into the slots. Air is admitted to the space between rotor and chamber wall through the air inlet 6, and, upon passing over the-groove 6a, the rotating fins produce *a suction effect which provides additional 1 air through the inlet tube into the chamber. As one fin-draws the air into the widest space between rotor andfichamber wall, the next fin compresses this air into "the narrower space as rotor and wall converge, The compressed air is forced into outlet I, through orifice 8, and across the top of tube l fl. The swiftness of the air current'causes a partial vacuum, and the liquid under atmospheric pressure in --the container flows up tube 1 5 into tube ill and is atomized at the top thereof by the current of ,air. It emerges from the expansion space or aperture 9 in an extremely fine-spray.

-When mineral oil-bas or kerosene-base insecticides or the like are employed in the container, the spray,-as aforesaid, is in substantially gaseous'form and .candrift in the air and permeate any cracks, .crevicesand fabric pores in the area where .itjis applied. This has the advantage of forming a blanket fog or vapor which excludes air and exterminates any insects and their eggs, larvae .and pupae with which it comes into contact. The vaporized insecticide thus provided hasthe additional advantage of being so finely atomized that it "tends to evaporate rather than to condense, so that no deposit is formed upon woodwork, "glassware, upholsteries and the like.

Our improved device "thus makes the use of a small, compact, inexpensive, portable sprayer entirely practicable for dispensing liquid insecticides, exterminants and the like having high killing power. This is provided at a cost suinciently low to be economical for use by householders, small storekeepers, bakeries, bars, grills,

ed on said casing substantially at right angles to said compressed air outlet and out of alignment with the shaft of the motor and having restaurants and any other places troubled by infestations of insect pests, no matter how small. It will be apparent from the description prvided that the spraying device and the container mutually supplement each other, the air-blowing and atomizing element being adapted for use with the container described and vice versa. It will be observed that our containers of. liquid insecticide can be marketed as individual articles of commerce and sold separately from the atomizing element, so that, when the content of a container has been used, it can be discarded and a full container purchased to replace it.

It has been found that very satisfactory results have been attained in practice when the tubular means for carrying the liquid content of the container into the stream of air is about inch in diameter, although diameters of about .02 inch to about .04 inch are operable. Likewise, we have employed a compressed air outlet having an orifice of about inch, although said orifice may vary from about inch to about inch. The compressor has a capacity of about 375 to about 400 cubic feet per minute, and liquid in the container is vaporized thereby at a rate of about K; of an ounce per minute.

Although our invention has been described in connection with a preferred embodiment thereof, it will be observed that variations and modifications may be resorted to, as those skilled in the art will readily understand. For example, a single long tube may be provided instead of tubes I 0 and in the preferred embodiment. This tube could be threadably connected to the cap I l and could be detached when not in use. Similarly, another variant of our invention is the provision of a spraying device and container constructed together and not demountable instead of the threadably connected unit set forth in our preferred embodiment. Such container would be adapted for refilling instead of being of the replaceable variety. These as Well as other variations and modifications, are intended to be within the scope of the present specification and the purview of the appended claims.

We claim:

1. A portable electric spraying device which comprises a motor-driven air compressor mounted in a casing and having a horizontal compressed air outlet in straight-line communication therewith; a first vertical open tube mountone end in the stream of air flowing from said outlet whereby a stream of compressed air blown through the outlet by the air compressor passes across the top of the open tube and creates a partial vacuum therein; a container adapted to hold a liquid and associated with said casing; a second tube mounted in said container and extending downwardly from the top thereof, said tube being spaced a short distance from the bottom of the container; means for tightly fixing the other end of said first tube in contact and substantial alignment with the upper endof said second tube; and means for keeping the surface of the liquid in the container under substantially atmospheric pressure, whereby said liquid is forced up through the tubes upon creation of a partial vacuum therein and is atomized by the stream of air, thereby providing a light, compact, easily operated sprayer adapted to vaporize liquid insecticides, exterminants and the like in an extremely fine spray and to form thereof a gaseous blanket which can displace air in the area of its application and can permeate cracks, crevices, pores and the like to kill insect pests therein without harmful elfect upon furnishings.

2. An atomizing and spraying device adapted to be secured to a threaded port of a liquid container having a straight tube extending from a point adjacent to the bottom of the container through said port; said. device comprising an air compressor housing; a threaded cap cast with said housing and integral therewith and adapted to make threaded engagement with the port of said container, said cap having an air inlet communicating with the interior of said container to maintain atmospheric pressure therein; a cylindrical chamber in said housing communicating with the atmosphere through an air inlet and a unidirectional compressed air outlet; a rotor having a plurality of slots extending inwardly from the periphery eccentrically mounted in said chamber; fins slidably mounted in said slots; motor means to rotate said rotor whereby air is drawn into said chamber through the air inlet, compressed and discharged into said compressed air outlet through which it flows as a substantially uniform air stream; and a second straight tube out of alignment with the shaft of the motor and extending from said cap in alignment with the top of the tube in said container to a position in said air stream.

WILLIAM F. GORDON. WALTER H. MARSH. 

